The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 22, 1998
Filed:
Sep. 16, 1997
Takashi Okawa, Fujioka, JP;
Shigeharu Iizuka, deceased, late of Hadano, JP;
Abstract
A detector is provided to optically monitor the outer periphery of a wafer rotated by rotation of a rotary stage, so as to detect how much the center of the wafer placed on the rotary inspection stage is offset from the rotational center of the rotary stage as well as an angular position, on the stage, of a V-shaped notch formed in the wafer. From the detected eccentricity of the wafer, it is determined whether a precise positioning operation, using at least three positioning pins, to locate the center of the wafer at the rotational center of the rotary stage should be performed or not. When the detected eccentricity is so great as to necessitate the precise positioning operation, one of the positioning pins is caused to fit into the V-shaped notch of the wafer on the basis of the detected angular position of the notch and then the precise positioning of the wafer is performed using the other two positioning pins. In this manner, the wafer can be properly positioned so that the center of the wafer lies exactly at the rotational center of the rotary stage, using the at least three positioning pins.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile